Star Nurseries (A.K.A. Nebulae): Hard!

Everyone knows the earth is full of beautiful sights like the Grand Canyon, Mt. Kilimanjaro and Angel Falls. But the entire universe is also full of mysterious and beautiful sights. One of them is nebulae.

According to http://library.thinkquest.org :

"Nebulae are conglomerates of gaseous and dust particles that spread throughout space. The gas is mostly made of hydrogen and helium. Dust in space is made of tiny particles of solid matter. Astronomers think stars are born in nebulae.

"There are many types of nebulae. The main types are planetary nebulae; diffuse nebulae; supernova remnants; reflection nebulae and dark nebulae. Planetary nebulae are “skin” (or shells) that an old, average-sized star sheds during the red giant stage. Diffuse nebulae are objects in space with no definite shape. Supernova remnants (or remains of supernovae) often give off radiation, which is like the radiation from TV or radio stations. A reflection nebula is made when a cloud of highly reflecting (maybe snow white) space particles is brightened by a nearby star whose temperature may not be hot enough to make the gas glow. Finally, there are dark nebulae. These are clouds are sometimes silhouetted by gas or the light of stars behind them."

Here are some questions regarding them. Either before or after you take the quiz, and if you have a fast internet connection, you may want to go to take a short video tour of the known nebulae at http://uk.youtube.com/watch?v=8x41n9thAU8&mode=related&search=

If your internet connection is slow, you may want to look through the archives at nebulae at http://antwrp.gsfc.nasa.gov/apod/

It will be worth your while! The photo accompanying this introduction, by the way, is of the Bubble Nebula.